Taking Nam Co basin as an example, we examine the interrelationship among vegetation growth, lake expansion, snow cover, and climate change, based on meteorological data and multisource remote sensing datasets. Results show that the climate has become warmer and wetter during the period of time from 1961 to 2010, with rates of () for annual mean temperature and () for annual precipitation, while the snow-covered index experienced a decreasing trend (, ) from 2003 to 2010. In response, the vegetation growth was deteriorative in most parts of the basin. Conversely, both the lake’s area and water level increased ( and , respectively). Although the enhanced vegetation index in the basin negatively correlates well with the lake’s area (, ), the correlation shows gradual decrease as distance away from the lake’s shoreline, from 25 km (zone A), to 25–50 km (zone B), and to 50–95 km (zone C). Two main factors might have contributed to this: (1) lake expansion buried grassland vegetation in zone A and (2) more gravel buildup and soil erosion due to runoff from snow melted water in zone A than in zones B and C. This study provides a scientific basis for the evaluation of changes in alpine grassland, lake, snow cover, and their responses to climate change.